Review of calcium antagonist trials in acute myocardial infarction

Nine randomized trials in patients with acute myocardial infarction have been performed to assess the effect of nifedipine on infarct size, reinfarction and/or survival. In none of the trials was there any benefit and in some there was a deleterious effect. In the most recent trial, SPRINT II, the study was stopped prematurely-because of deleterious side effects in the diltiazem-treated group. Thus, nifedipine is not recommended in patients with acute myocardial infarction or postmyocardial infarction for prevention of reinfarction or death, and further trials are not necessary. In a single study involving 1,436 patients, verapamil showed no statistical benefit on reinfarction or survival, but due to a high drop-out rate, the result appears less than definitive. A second trial has been completed but results are not yet available. In a randomized, double-blind short-term (2 weeks) trial consisting of 576 patients with non-Q-wave infarction, diltiazem caused a 50% reduction in the incidence of reinfarction and refractory angina. In a long-term trial (12-52 mos.) consisting of 2,466 patients with Q- and non-Q-infarction, there was no benefit overall, but in the patients without failure (80%) there was a 28% reduction in cardiac events. In the patients with non-Q-infarction (634), there was a 40% reduction in cardiac events, and at the end of 4-5 years there was still a reduction of 34% in the diltiazem group. In patients admitted to the study with failure, the mortality was increased in patients with Q- or non-Q-infarction. Thus, diltiazem is recommended for routine prophylaxis in patients with non-Q-infarction without cardiac failure.